Making Colours from certain Chemicals.Watch
I need help with some Chemistry Homework. I have been asked to create certain colours from with only a limited supply of chemicals.
The Chemicals Provided:
1. Copper II Carbonate
2. Sulfuric Acid 1M
3. Ammonia Solution 2M
4. Distilled Water
6. Potassium Iodide
7. Aqueous Chlorine
8. Starch Solution
9. Steel Wool
10. Sodium Thiosulphate.
1) Dark Blue Solution
2) A blue/Black Solution
3) A purple Solution
4) Green Precipitate
5) Blue Crystals
6) Black Solid
7) White Precipitate
8) Brown/ Red Precipitate
Any help would be great thanks!
Blue/black-bubble chlorine gas through potassium iodide to form iodine, then add starch solution
Purple solution-bubble chlorine though potassium iodide again, to form iodine then add cyclohexane- a separate organic layer forms which contains purple dissolved iodine (iodine is often purple in organic solvents).
Green precipitate-dissolve steel wool in sulfuric acid, to form iron (II) sulfate solution, then add ammonia solution (which contains OH- ions), a green precipitate would be formed of iron (II) hydroxide.
Blue crystals- dissolve copper carbonate in sulfuric acid, slowly evaporate the copper sulfate solution that is formed to produce blue copper sulfate pentahydrate crystals.
Black solid- heat copper carbonate at high temperatures, thermal decomposition occurs and black copper (II) oxide is formed
White precip.- add sulfuric acid to sodium thiosulfate, precipitate of white/yellow sulfur formed.
Red precipitate- dissolve iron in sulfuric acid, bubble air or chlorine through the iron (II) sulfate solution to oxidise it to iron (III).
Then add ammonia solution again- to form iron (III) hydroxide.
I know these reactions due to my life long interest in amateur chemistry, and have performed these experiments in real life.
Hope that helps!